Spoiled Meat is very easy to produce in Ark. In fact, it is pretty near impossible to avoid it. But it does have its uses. It is used to create Narcotics, whcih are used in Taming and in some of the Rockwell Recipes. Narcotics are also used for the fabrication of ammo and explosives.
Producing spoiled meat is easy. By default, Raw Meat will Spoil in 10 minutes. Raw Prime Meat will spoil in 2 minutes. Cooked Meat and Cooked Prime Meat also spoil. This all produces Spoiled Meat.
But how do you produce a lot of it? In your inventory. The way the stack and spoiling system works is simple. Let's take a single stack of Raw Meat. It will spoil in 10 minutes in your inventory. That doesn't mean the whole stack, though. It will one spoil one piece at a time, meaning the whole stack of 20 Raw Meat will take 200 minutes to spoil. The trick is to spilt the stack! Click any stack in your inventory, hold down shift and drag. The stack will be split evenly into two stacks. Repeat until you have 20 stacks of 1. They are all going to spoil in less than 10 minutes. This will leave you with 20 Spoiled Meat.
After a big hunting expedition, you could easily end up with 100 Raw Meat, so just split those stacks down to stacks of one every time you harvest more meat and before long you'll have a ton of Spoiled Meat.
As for the preservation of Spoiled Meat, it's pretty simple. Just toss it into a Preservation Bin or Fridge!